Machine for plane grinding piston rings



MACHINE FOR PLANE GRINDING PISTON RINGS Filed Aug. 30, 1934 2 Sheets-Sheet l March 17, 1936. E. JUNKER MACHINE FOR PLANE GRINDING PISTON RIENGS 2 Sheets-Sheet 2 Filed Aug. 30, 1934 Patented Mar. 17, 1936 PATET MACHINE FOR PLANE GRINDING PISTON RINGS Emil Junker, Zurich, Switzerland 1 Claim.

The present invention relates to an improved means for the mass production of piston rings and more particularly to a device for the machining of the piston rings.

The main object of the invention is to provide an improved automatic machine for the finishing of the ring side faces by grinding and honing to obtain a good finish and perfect accuracy.

It has been proposed to use a double disc grinding machine for simultaneously grinding both the side faces of the piston rings. The machines used for such purpose have the disadvantage that the piston rings have had to sustain a certain strain which led to distortion.

It is an object of the present machine to obviate the disadvantages of the previous machines in that the piston rings are passed uniformly between the two. inclined grinding discs free from pressure and tension, without the piston rings coming into contact with one another.

I obtain the said object by feeding the piston rings by an endless band which is drawn between the two discs and which is provided with openings in which the piston rings are located free from tension.

The feeding speed can be adjusted by varying the speed of the band. The piston rings are accurately guided in front of and beyond the grinding discs between rails so that the piston rings are not damaged by the grinding discs when entering and leaving.

An example of construction of the subject of the invention is shown diagrammatically in the accompanying drawings, wherein:

Fig. 1 shows the lay-out of the machine in plan;

Fig. 2 is a cross-section on the line AB of Fig. 1;

Figs. 3 and 4 show a plan and longitudinal section of the carrier-band for the piston rings.

Fig. 5 shows in sectional elevation the device for inserting the piston rings into openings of the endless band;

Figs. 6 and 7 are sections on lines CD and EF of Fig. 5, respectively.

In a frame 23 two grinding discs I and 2 are secured to spindles 3 and 4 respectively. The latter run in the bearings 5, 6 and'l, 8 of the frame 23. Separate motors 3 and it drive the grinding spindles 3 and 4 through elastic clutches II and I2. Between the grinding discs I and 2 is passed an endless band I3 for instance of hardened steel, which serves as a carrier of the piston rings I8 and which runs in the direction of the arrow I. The band I3 passes over three rollers I5, I6, I! of which at least one is driven by a motor not shown in the drawing. The band I3 is provided with openings 24 which are sufliciently large to receive each a piston ring 68 to be treated, the piston ring resting loosely in the 5 opening without pressure and thus without tension. The thickness of the band it is less than the width of the piston rings It to be treated, which is about two millimeters, the band itself therefore is not ground when passing between 10 the grinding discs I and 2. The piston rings I8 are placed into the band I3 by means of a device for automatically feeding the same. Directly adjacent the grinding discs I and 2 are provided guide rails I9, 20 for the entrance and 15 2 I, 22 for the outward passage of the piston rings I 8. These guide rails lead each piston ring I 8 accurately between the discs I and 2 so that the latter cannot damage the rings. The spindles of the discs I and 2 are placed at an angle to 20 each other so that the working faces of the discs are not parallel to one another but are more or less inclined relatively to one another in accordance with the layer to be ground off by the discs I and 2. The piston rings I8 are brought be- 25 tween the working faces of the discs where the gap between them is wider. The movement of the band is kept as uniform as possible in order to maintain the feed of the rings. to the operative position uniform. 30

To insert a piston ring I8 in the openings 24 the feeding device shown in Figs. 5, 6 and '7 is used. The device comprises a support 25 and a vertical wall 33. The set of piston rings I8 rests on a slanting face of the support 25 and on the 35 vertical face of the wall 33. A plate 28 sliding on a bar 34 pushes the set of piston rings it against the endless band I3. To the plate 28 the one end of a belt 29 is fixed. The belt runs over a pulley 30 and carries a weight 3|. The latter exerts a constant pressure on the pile of piston rings I8. While the band I3 passes in front of the pile, the piston rings are inserted one by one in the openings 24. The piston rings 45 are pressed against the adjustable plate I9 and are passed between the plates I 9, 20 to the grinding discs I, 2. Care is being taken that the gap between the plates I9, 20 coincides exactly with the gap between the discs I, 2 both the plates 50 I9 and 20 being adjustably mounted by some well known means. The band I3 slides over the faces of guide bars 26, 21, and it runs in a vertical plane at the centre of the gap.

It W111 be seen that the Weight 35 sustained 55 by the cord 35 passing over pulley 31 adjusts the roller IE to keep the band taut.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:-

In a machine for grinding and honing piston rings and the like, two rotary grinding discs rotatable on axes located in a horizontal plane,

10 a thin flexible endless band passing between said grinding discs approximately parallel to the faces thereof, a set of guide rollers around which said band is passed, the axes of said rollers lying normal to said horizontal plane, said band having openings through the same loosely to receive the rings to be ground and completely to encircle the rings and being of less thickness than that of the rings, and means to maintain said band constantly under tension.

- E. JUNKER. 

